The present invention relates generally to the field of lasers and wavelength conversion devices and more particularly to a tunable solid state laser and process of altering a wavelength of a light emitting diode.
Tunable lasers are useful in a variety of applications, including optical pumps and spectrometry. Presently, dye lasers provide some tuning range. These lasers use a variety of dyes to provide a wide range of wavelengths. Unfortunately, the dye in these lasers tends to degrade quickly due to UV (ultraviolet) light from pump sources. In addition, dye lasers tend to have a narrow absorption band that limits their overall efficiency. Other tunable laser include Ti (Titanium) sapphire, ruby and alexandrite lasers. These lasers are all solid state laser and therefor do not suffer from the degradation problems of dye lasers. In addition, Ti sapphire has a broad tuning range. Unfortunately, Ti sapphire lasers are not scalable up to higher powers. In addition, there is always a need for a broader tuning range.
Thus there exists a need for a highly tunable laser in which the lasing material does not degrade or degrades very slowly and has a broader absorption band.
Another problem is white light LEDs (Light Emitting Diodes). Presently, white light LEDs are formed by combining a red, green and blue diodes. This is expensive since it requires three diodes. Another method of forming white light LEDs is by doping the substrate of a blue LED with an element. The doped substrate converts some of the blue light to a longer wavelength. The combination the longer wavelength light and blue light forms a xe2x80x9cwhitexe2x80x9d light. Unfortunately, the light from the prior art white light LEDs do not meet the highest quality color.
Thus there exists a need for a white light LED that is inexpensive and produces a broad, fairly flat, spectrum.